ABSTRACT
Maps depicting the geographic and bathymetric ranges of the order Clypeasteroida serve in the interpretation of changes in environmental parameters of this group in space and time. The geographic and bathymetric ranges of 110 extant clypeasteroid species are mapped individually, but are combined at the generic level for convenience of presentation. The primary data were compiled from Mortensen’s monograph and supplemented by other works. Bathymetric ranges of most clypeasteroids are largely confined to the continental shelf areas though the genus Echinocyamus has been found beyond the shelf margin. Cosmopolitan communities appear at first to dominate most biotic provinces; it is, however, necessary to examine the assemblages at the species level to delineate and identify endemic and relict populations. No clypeasteroids are found in Antarctic waters. The particular distributional patterns of the endemic and relict echinoid species cannot be explained by vicariance events, suggesting that other biologic mechanisms are involved.
